One other more obvious thing is search engine optimisation (SEO) - have a look at your server logs for the sorts of queries people use to find you e.g. "Linux news". I just checked and LWN is very low on first page for https://www.google.com/search?q=linux+news
Then make sure your home page is optimised for the keywords you want to use (ask an SEO expert for how to choose them) - for example, "Welcome to LWN.net" is a truly terrible <TITLE> tag as it doesn't even mention Linux or news (assuming the "linux news" keyword is what you should optimise for, which is likely).
There is a lot you can do with "onsite SEO" that is subtle and won't annoy readers - you already have outstandingly good content so it's probably just writing a couple of pages that talk about LWN and what it provides, I would guess. On the "offsite SEO" i.e. links from other sites, it's important that only reputable link building is done, using your chosen "linux news" type keyword in the <a href> link text on the other site. Finding a good SEO expert through personal recommendation is important, or you could go to http://www.seobook.com/ or http://www.seomoz.org/resources and learn about SEO, if you prefer to do it yourself.
The community could help with link building of course - once you've decided on the right keywords and pages to point the links at, you can have a "link to us" page that encourages the community to put badges and links on their blogs etc, getting free links from people who like LWN - better than doing your own link building in fact.
Since you already have great content and community this would be much easier than a new site, but it needs to be done in the right way.
Any updated site design should as a minimum be based on SEO, so that the time/cost put into this gives you an SEO benefit.